At the "Authentication.php" Controller, comment out or remove the following lines of code:
Line 91:
//$isRTL = $this->app_lib->getRTLStatus($language);
Line 102:
// 'is_rtl' => $isRTL,
Line 241 to 263:
/*private function loginLog($userID = 0, $role = 0, $branchID = '')
{
}*/
OR
Replace the "Authentication.php" Controller file, with the attached PHP file.